Cognitive impairment has a strong relation to nonsomatic symptoms of depression in relapsing-remitting multiple sclerosis

Relationship between neuropsychiatric symptoms and cognition in multiple sclerosis: A systematic review

The results of previous research on the relationship between neuropsychiatric symptoms and cognition in multiple sclerosis (MS) have been mixed. The aim of this systematic review was to examine the evidence on the relationship between neuropsychiatric symptoms and different cognitive domains in adult (≥18 years) MS patients. A literature search was conducted in the Ovid Medline, PsycInfo, Scopus, and Web of Science databases. A total of 4,216 nonduplicate records were identified, and after screening, 37 studies met the inclusion criteria and were included in the systematic review. Higher levels of depressive symptoms were related to deficits in processing speed, verbal memory, executive functions, visuospatial functions, and attention in MS patients. Symptoms of anxiety were not consistently related to any of the cognitive functions, but the relationship to deficits in visual memory received a minimal amount of support. Higher levels of apathy were most clearly associated with impairment in executive functions, but the association with deficits in visuospatial functions, visual memory, working memory, and processing speed was also supported. The results indicate that more neuropsychiatric symptoms, especially depressive symptoms and apathy, are associated with cognitive dysfunction in MS patients. These results can be utilized in the clinical examination and treatment planning of MS patients.

The relationship between depression and cognitive performance in multiple sclerosis: A meta-analysis

Objective: Studies on the relationship between depression and cognition on patients with multiple sclerosis (MS) are inconsistent and it is not clear whether higher depression levels are associated with impairment of specific cognitive domains or processes. This meta-analytic study aimed at evaluating the possible association between depressive symptomatology and performance on cognitive tests assessing several cognitive domains (global cognition, attention, processing speed, verbal, spatial and working memory, verbal fluency, inhibitory control, set-shifting) in individuals living with MS. Method: The literature search on three electronic databases yielded 5402 studies (4333 after the duplicates removal); after the evaluation of titles, abstracts full-text articles, 37 studies were included in the meta-analytic study. A random-effect model meta-analysis was performed and mean weighted effect sizes (ESs) were calculated using Hedges' g. Results: Small ESs were found for the relationship between depression and verbal memory (g = 0.25, p < 0.001), spatial memory (g = 0.23, p < 0.001), verbal fluency (g = 0.26, p < 0.001), and inhibitory control (g = 0.32, p = 0.003). Medium ESs were found for the relationship between depression and global cognition (g = 0.46, p < 0.001), attention (g = 0.43, p < 0.001), processing speed (g = 0.47, p < 0.001) and working memory (g = 0.38, p = 0.037). The relationship between set-shifting abilities and depression was not significant (g = 0.39, p = 0.095). Conclusions: Results suggest that patients with MS and higher levels of depressive symptomatology may also show more difficulties in several aspects of cognition, especially those needed to retain, respond, and process information in one's environment, and to those needed be adequately stimulated in processing relevant information.

Assessment of cognitive function and its predictors in patients with multiple sclerosis: a case-control study

INTRODUCTION

Cognitive dysfunction can be seen in patients with MS (PwMS) and has been gaining attention in recent years. This study aimed to assess cognitive function and its determinants in PwMS using Addenbrooke Cognitive Assessment Battery (ACE-R).

MATERIAL AND METHODS

This case-control study was conducted at an outpatient MS clinic in Istanbul. The sample consisted of 60 consecutive patients with definite MS and 60 matched controls. Cognitive function was evaluated by using the ACE-R. Subjective cognitive function, anxiety, depression, and fatigue were evaluated by validated scales.

RESULTS

The mean age of the patients was 38.8, and the time since diagnosis was nine years. The majority of the patients had relapsing-remitting MS. Compared to age, sex, and education-matched healthy controls, all ACE-R scores, attention/orientation (p = 0.020), memory (p = 0.003), verbal fluency (p = 0.002), language (p = 0.002), visuospatial (p = 0.001), and general cognitive functioning (p < 0.001), were found to be lower in PwMS. The patients obtained the lowest scores in memory and fluency and the highest in the visuospatial domain. Age, education, mobility, subjective cognitive dysfunction, anxiety, depression, and fatigue were associated with cognitive test scores. However, only education, depression, and fatigue remained significant in the multivariable analysis.

CONCLUSION

This study revealed impaired domains of cognitive functioning and its predictors in PwMS. Understanding cognitive dysfunction and its predictors in PwMS may enable healthcare providers to identify patients who might benefit from interventions to improve cognitive function. Assessment of PwMS at outpatient clinics with a practical cognitive test that does not require special competence can be suggested.

Co-occurrence of Fatigue and Depression in People With Multiple Sclerosis: A Mini-Review

Fatigue and depression are common conditions diagnosed in people with multiple sclerosis (MS). Fatigue defined as subjective lack of physical and/or mental energy is present in 35–97% of people with MS, who classify it as one of the most serious symptoms interfering with daily activities and influencing the quality of life. Depression is diagnosed in about 50% of people with MS. Since fatigue and depression frequently coexists, it may be quite hard to differentiate them. Primary fatigue and primary depression in MS are caused by inflammatory, oxidative/nitrosative, and neurodegenerative processes leading to demyelination, axonal damage, and brain atrophy. In people with MS and comorbid fatigue and/or depression there is reported increased serum and cerebrospinal fluid concentration of inflammatory mediators such as tumor necrosis factor, interleukins (IL-1a, IL-1b, IL-6), interferon γ and neopterin. Moreover, the brain atrophy of prefrontal, frontal, parietotemporal regions, thalamus, and basal ganglia was observed in people with MS with fatigue and/or depression. The secondary fatigue and secondary depression in people with MS may be caused by emotional factors, sleep disorders, pain, the coexistence of other diseases, and the use of medications. In some studies, the use of disease-modifying therapies positively influenced fatigue, probably by reducing the inflammatory response, which proves that fatigue and depression are closely related to immunological factors. In this mini-review, the pathogenesis, methods of evaluation and differentiation, and possible therapies for fatigue and depression in MS are discussed.

Effects of transcranial direct current stimulation on cognitive dysfunction in multiple sclerosis

BACKGROUND

Around 40%-70% of patients with multiple sclerosis (MS) may experience cognitive impairments during the course of their disease with detrimental effects on social and occupational activities. Transcranial direct current stimulation (tDCS has been investigated in pain, fatigue, and mood disorders related to MS, but to date, few studies have examined effects of tDCS on cognitive performance in MS.

OBJECTIVE

The current study aimed to investigate the effects of a multi-session tDCS protocol on cognitive performance and resting-state brain electrical activities in patients with MS.

METHODS

Twenty-four eligible MS patients were randomly assigned to real (anodal) or sham tDCS groups. Before and after 8 consecutive daily tDCS sessions over the left dorsolateral prefrontal cortex (DLPFC), patients' cognitive performance was assessed using the Cambridge Brain Sciences-Cognitive Platform (CBS-CP). Cortical electrical activity was also evaluated using quantitative electroencephalography (QEEG) analysis at baseline and after the intervention.

RESULTS

Compared to the sham condition, significant improvement in reasoning and executive functions of the patients in the real tDCS group was observed. Attention was also improved considerably but not statistically significantly following real tDCS. However, no significant changes in resting-state brain activities were observed after stimulation in either group.

CONCLUSION

Anodal tDCS over the left DLPFC appears to be a promising therapeutic option for cognitive dysfunction in patients with MS. Larger studies are required to confirm these findings and to investigate underlying neuronal mechanisms.

Depression and Fatigue in Patients With Multiple Sclerosis Have No Influence on the Parameters of Cognitive Evoked Potentials

PURPOSE

The purpose of this study was to examine if depression and fatigue affect event-related brain potentials (ERPs) in patients with relapsing-remitting multiple sclerosis, and to assess the significance of ERP as an indicator of cognitive impairment.

METHODS

A total of 81 relapsing-remitting multiple sclerosis patients and 32 healthy control subjects participated in the study. Cognitive functions were evaluated using a standard PASAT, the symbol digit modality test, and ERP. The degrees of depressive symptomatology and fatigue were assessed with Beck Depression Inventory, the Fatigue Severity Scale, and the Fatigue Impact Scale.

RESULTS

Fatigue and depression had a negative effect on the cognitive functions examined by neuropsychological tests. Depression and fatigue did not influence ERP amplitude and latency findings. Depression level was negatively correlated with symbol digit modality test score (r = -0.135, P < 0.05). Fatigue level was negatively correlated with the results for PASAT A (r = -0.225, P < 0.05) and PASAT B (r = -0.342, P < 0.01). Reaction time was positively associated with depression (r = 0.246, P = 0.01) and fatigue (r = 0.281, P = 0.01).

CONCLUSIONS

Depression and fatigue have no effect on ERP amplitude and latency, so they cannot participate in risk assessment for the development of cognitive impairment in patients with relapsing-remitting multiple sclerosis.

Effects of diminished positive mood and depressed mood upon verbal learning and memory among people with multiple sclerosis

Objective: Cognitive impairment affects as many as 65% of people with multiple sclerosis (PWMS), and memory impairment confers greater severity of disability and functional impairment. Depression is also common among PWMS, and lifetime prevalence rates are as high as 50%. Research has yet to clearly define the relationship between memory dysfunction and depression among PWMS, and may reflect incomplete assessment of depressive symptoms. The present study examined different aspects of depressive symptoms including anhedonia (i.e., diminished positive mood) and their relationships with verbal learning and memory among PWMS.Method: Participants were 48 healthy individuals and 96 PWMS. They were primarily Caucasian (90.3%) and female (75.0%). Participants completed the California Verbal Learning Test-2 (CVLT-2) to assess verbal learning and memory and the Chicago Multiscale Depression inventory to assess depressed mood (CMDI-Mood) and diminished positive mood (CMDI-DPM).Results: Linear regression revealed that the main effect of CMDI-DPM and the interaction of CMDI-DPM and CMDI-Mood significantly explained variance across learning, recall, and recognition CVLT-2 indices. Follow-up analyses indicated that CMDI-DPM was only significant in the absence of high CMDI-Mood scores. CMDI-Mood explained variance in only CVLT-2 Trial B.Conclusions: Depressed mood had little direct effect upon memory performance in PWMS. In the absence of severe depressed mood, higher levels of positive mood corresponded to better memory performance. However, the impact of diminished positive mood was rendered null among those endorsing high levels of depressed mood. These data may imply that anhedonia corresponds with poorer memory function among PWMS, and suggests that investigators and clinicians should assess multiple mood dimensions among PWMS.

Demographic features, behavioral measures, and clinical factors as predictors of cognitive function in patients with multiple sclerosis

BACKGROUND

One of the most concerning features that involves 40-70% of patients with multiple sclerosis (MS) is cognitive impairment. Moreover, it affects various aspects of patients' life. In this regard, this study was conducted to find independent predictors of cognitive function.

METHOD

We performed a cross-sectional analysis on 92 patients chosen from MS clinic of Sina hospital, Iran. After completing a general questionnaire of demographic and various clinical features, the included participants (patients with RRMS) underwent neuropsychological assessment using Minimal Assessment of Cognitive function in Multiple Sclerosis (MACFIMS), Expanded disability Status Scale (EDSS), Beck Depression Inventory II (BDI-II), and National American Adult Reading Test (NAART). An un-weighted average of MACFIMS subscales z-scores was reported as cognitive index. In order to find the association between CI and different factors, each variable was entered in a simple regression model first. Then, a univariate multiple regression model was invoked to evaluate the predictors of cognitive index in patients.

RESULTS

Simple regression for cognitive index of 92 patients (86% female) with a mean age of 33.4±7.6 years old suffering of RRMS for 6.8±4.8 years revealed patients with history of former smoking (p=0.001), sole visual symptoms as the presentation sign of the study (β=-0.341, p=0.001), lower EDSS score (β=-0.299, p=0.005), higher NAART score (β=0.416, p≤0.0001), and college education (p=0.001), had better cognitive function in our study population. Such factors including age, educational status, BDI-II score, EDSS score, and disease duration were fixed and the other significant factors entered once separately and then simultaneously in the univariate multiple linear regression model. It was revealed that former smoking (β=-0.372, p≤0.0001), NAART (β=0.304, p=0.002), and EDSS (β= -0.185, P=0.045) are associated significantly with the cognitive function of patients with multiple sclerosis.

CONCLUSION

This study demonstrated NAART, as a proxy of premorbid intelligence, history of former smoking, and EDSS score may have effects on cognitive function in MS. Future studies need to be invoked for the evaluation of the causality relation of these factors.

The Effect of Cognitive Rehabilitation on Balance Skills of Individuals with Multiple Sclerosis

Balance skills can be affected by slow information processing speed in people with multiple sclerosis. This study explored the effect of cognitive-based rehabilitation on balance skills of individuals with multiple sclerosis. Seventy-one participants with multiple sclerosis were randomly assigned to the usual occupational therapy exercises as a control group (n = 36, male = 10) or the cognitive rehabilitation group (n = 35, male = 10). Using several assessments pre-intervention, post-intervention and two months after completion, participants in the cognitive rehabilitation group showed significant improvement in their balance skills in post-test and as well as follow-up measurements compared to the control group. Results also showed a large effect of cognitive rehabilitation for balance (eta-squared= 0.59) and for information processing speed measured. Inclusion of tasks related to information processing speed to the usual occupational therapy exercises seemed to be able to improve the balance skills of people with multiple sclerosis.

The emotional disorders associated with multiple sclerosis

Multiple sclerosis (MS) is associated with a high prevalence of emotional and mood disorders. Emotional disorders may worsen during illness progression and affect the quality of life of patients and their families. MS is often associated with depression, with an increased risk of suicide, poor adherence to treatment, decreased functional status, and quality of life. The diagnosis and treatment of emotional and mood disorders in these patients is often challenging since several symptoms of these disorders overlap with those of MS. Other prevalent emotional disorders in MS include bipolar disorder, anxiety disorders, emotional blunting (apathy), and pseudobulbar affect. Early recognition and treatment of these comorbidities could contribute to the reduction of disability and even to decreased mortality. The aim of this chapter is to provide an up-to-date review of mood and emotional disorders that are often associated with MS, focusing on their epidemiology, clinical features, pathogenesis, assessment, and treatment. The interplay between the psychosocial impact of the chronic disability and the demyelinating structural lesions of the brain in precipitating emotional and mood disorders is discussed, as well as its implications for diagnosis and treatment.

Mechanism of visual network dysfunction in relapsing-remitting multiple sclerosis and its relation to cognition

OBJECTIVE

To investigate if changes in brain network function and connectivity contribute to the abnormalities in visual event related potentials (ERP) in relapsing-remitting multiple sclerosis (RRMS), and explore their relation to a decrease in cognitive performance.

METHODS

We evaluated 72 patients with RRMS and 89 healthy control subjects in a cross-sectional study. Visual ERP were generated using illusory and non-illusory stimuli and recorded using 21 EEG scalp electrodes. The measured activity was modelled using Dynamic Causal Modelling. The model network consisted of 4 symmetric nodes including the primary visual cortex (V1/V2) and the Lateral Occipital Complex. Patients and controls were tested with a neuropsychological test battery consisting of 18 cognitive tests covering six cognitive domains.

RESULTS

We found reduced cortical connectivity in bottom-up and interhemispheric connections to the right lateral occipital complex in patients (p < 0.001). Furthermore, interhemispherical connections were related to cognitive dysfunction in several domains (attention, executive function, visual perception and organization, processing speed and global cognition) for patients (p < 0.05). No relation was seen between cortical network connectivity and cognitive function in the healthy control subjects.

CONCLUSION

Changes in the functional connectivity to higher cortical regions provide a neurobiological explanation for the changes of the visual ERP in RRMS.

SIGNIFICANCE

This study suggests that changes in connectivity to higher cortical regions partly explain visual network dysfunction in RRMS where a lower interhemispheric connectivity may contribute to impaired cognitive function.

Neuropsychological characteristics of benign multiple sclerosis patients: A two-year matched cohort study

BACKGROUND

The definition of benign multiple sclerosis (BMS) is still debated. It is mainly based on physical status, however, there is an attempt to involve cognitive functioning or paraclinical factors in order to avoid unnecessary long-term treatment with disease-modifying therapies and to identify these subjects in the early stages of the disease. Therefore the aim of our two-year follow-up study was to investigate the pattern of cognitive functioning and depression in patients with BMS compared to treated relapsing-remitting MS (RRMS) patients and healthy controls.

METHODS

A group of 22 BMS patients was tested against matched RRMS patients and healthy controls. All individuals underwent neuropsychological evaluation exploring mood and the cognitive domains most frequently impaired in MS. MS patients were retested at two-year follow-up.

RESULTS

In terms of cognitive functions there were no differences between BMS and RRMS patients either at baseline or at two-year follow-up. Compared to healthy controls BMS patients showed poorer performance in long-term visuo-spatial memory and information processing speed, whereas, complex attention, working memory, long-term verbal memory - despite slower verbal learning - and executive function were found to be intact. RRMS patients showed significant difference in complex attention, long-term visual memory and information processing speed. Cognitive impairment differed in the patient groups in terms of severity. Both patient groups were depressed compared to controls, but significant differences were found only between BMS and healthy individuals.

CONCLUSION

The results of our study confirm that cognitive functions and mood can be affected in MS independent of disease course and disease modifying treatment. The "benign" label should be treated as only a reference to physical status and non-motor symptoms should be routinely monitored. Without receiving therapy it is an existing entity with longstanding minimal disability.

Cognitive Fatigue in Multiple Sclerosis: An Objective Approach to Diagnosis and Treatment by Transcranial Electrical Stimulation

Cognitive fatigue is one of the most frequent symptoms in multiple sclerosis (MS), associated with significant impairment in daily functioning and quality of life. Despite its clinical significance, progress in understanding and treating fatigue is still limited. This limitation is already caused by an inconsistent and heterogeneous terminology and assessment of fatigue. In this review, we integrate previous literature on fatigue and propose a unified schema aiming to clarify the fatigue taxonomy. With special focus on cognitive fatigue, we survey the significance of objective behavioral and electrophysiological fatigue parameters and discuss the controversial literature on the relationship between subjective and objective fatigue assessment. As MS-related cognitive fatigue drastically affects quality of life, the development of efficient therapeutic approaches for overcoming cognitive fatigue is of high clinical relevance. In this regard, the reliable and valid assessment of the individual fatigue level by objective parameters is essential for systematic treatment evaluation and optimization. Transcranial electrical stimulation (tES) may offer a unique opportunity to manipulate maladaptive neural activity underlying MS fatigue. Therefore, we discuss evidence for the therapeutic potential of tES on cognitive fatigue in people with MS.

Symptoms of fatigue and depression is reflected in altered default mode network connectivity in multiple sclerosis

Background

Fatigue and depression are frequent and often co-occurring symptoms in multiple sclerosis (MS). Resting-state functional magnetic resonance imaging (rs-fMRI) represents a promising tool for disentangling differential associations between depression and fatigue and brain network function and connectivity. In this study we tested for associations between symptoms of fatigue and depression and DMN connectivity in patients with MS.

Materials and methods

Seventy-four MS patients were included on average 14 months after diagnosis. They underwent MRI scanning of the brain including rs-fMRI, and symptoms of fatigue and depression were assessed with Fatigue Severity Scale (FSS) and Beck Depression Inventory II (BDI). A principal component analysis (PCA) on FSS and BDI scores was performed, and the component scores were analysed using linear regression models to test for associations with default mode network (DMN) connectivity.

Results

We observed higher DMN connectivity with higher scores on the primary principal component reflecting common symptom burden for fatigue and depression (Cohen’s f² = 0.075, t = 2.17, p = 0.03). The secondary principal component reflecting a pattern of low fatigue scores with high scores of depression was associated with lower DMN connectivity (Cohen’s f² = 0.067, t = -2.1, p = 0.04). Using continuous mean scores of FSS we also observed higher DMN connectivity with higher symptom burden (t = 3.1, p = 0.003), but no significant associations between continuous sum scores of BDI and DMN connectivity (t = 0.8, p = 0.4).

Conclusion

Multivariate decomposition of FSS and BDI data supported both overlapping and unique manifestation of fatigue and depression in MS patients. Rs-fMRI analyses showed that symptoms of fatigue and depression were reflected in altered DMN connectivity, and that higher DMN activity was seen in MS patients with fatigue even with low depression scores.

Performance in daily activities, cognitive impairment and perception in multiple sclerosis patients and their caregivers

Background

The relationship between cognitive assessment results in multiple sclerosis (MS) and performance in daily activities (DAs) remains unclear. Our study aimed to evaluate the relationship between cognitive functions (CF) measured by tests, performance in DAs, and the perception of CF in patients and their caregivers (CG) in MS.

Methods

The Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) battery was used to evaluate cognitive status. We created an ad hoc questionnaire (DaQ) to assess performance in DAs not requiring specific motor skills. We used the Multiple Sclerosis Neuropsychological Questionnaire (MSNQ) to measure each patient self-judgment and caregiver’s perception of CF.

Results

Forty-nine patients and their caregivers were included in the study. Significant correlations were found between the BICAMS and the DaQ (Symbol Digit Modalities Test (SDMT): r = − 0.48, p < 0.001; California Verbal Learning Test (CVLT): r = − 0.33, p = 0.01; Brief Visual Memory Test (BVMT-R): r = − 0.42; p = 0.002); patients self-judgment (SDMT: r = − 0.38, p = 0.004; CVLT: r = − 0.26, p = 0.03); caregiver perception of patient’s CF (SDMT: r = − 0.52, p < 0.001; CVLT: r = − 0.3, p = 0.01; BVMT-R: r = − 0.42, p = 0.002). The difference in perception between the patients and their caregivers was related to patient age (p = 0.001) and severity of cognitive impairment (p = 0.03).

Conclusions

Cognitive assessment results show a significant correlation with performance in daily activities and with patients and, especially, caregiver perception of cognitive impairment. These data support the importance of a routine evaluation of cognitive function in MS that includes an anamnestic evaluation of patients, and, when possible, consideration of the caregiver’s point of view.

Electronic supplementary material

The online version of this article (10.1186/s12883-018-1224-z) contains supplementary material, which is available to authorized users.

The Role of Information Processing Speed in Clinical and Social Support Variables of Patients with Multiple Sclerosis

BACKGROUND AND PURPOSE

Information processing speed is one of the most impaired cognitive functions in multiple sclerosis (MS). There are two tests widely used for evaluating information processing speed: the Symbol Digit Modalities Test (SDMT) and the Paced Auditory Serial Addition Test (PASAT). To analyze the relationship between processing speed and the clinical and social support variables of patients with MS.

METHODS

A group of 47 patients with relapsing-remitting MS was studied, 31 were women and 16, men. Age: 39.04±13.17, years of schooling: 13.00±3.87, Expanded Disability Status Scale (EDSS): 2.78±1.81, and disease evolution: 8.07±6.26. Instruments of measure; processing speed: SDMT, PASAT, clinical variables: EDSS, Fatigue Severity Scale (FSS), Beck's Depression Inventory II (BDI-II), and social support: Medical Outcomes Study Social Support Survey (MOS).

RESULTS

Significant correlations were found between information processing speed and psychiatric, motor disability and social support variables. The SDMT correlated significantly and negatively with BDI-II, FSS, EDSS, and MOS (p<0.05), whereas the PASAT correlated negatively with FSS and positively with MOS (p<0.05). Information processing speed appeared as the performance predictor of these variables. The SDMT produced significant changes in EDSS (R²=0.343, p=0.000); FSS (R²=0.109, p=0.031); BDI-II (R²=0.124, p=0.018), and MOS (R²=between 0.212 and 0.379, p<0.05).

CONCLUSIONS

Information processing speed has influence on the clinical variables and the social support of patients with MS. These aspects are important to bear in mind for therapeutic approach.

Longitudinal Stability of Cognition in Early-Phase Relapsing-Remitting Multiple Sclerosis: Does Cognitive Reserve Play a Role?

Background

Up to 70% of people with multiple sclerosis (MS) experience cognitive impairment. Some remain cognitively intact despite advanced disease. Cognitive reserve (CR) theory postulates that individuals with higher levels of intellectual enrichment can tolerate more pathology than others before exhibiting cognitive impairment.

Methods

Thirty-two individuals with early-phase relapsing-remitting MS with mild physical disability and disease duration less than 10 years and 32 controls were recruited. At baseline and after 3 years, participants completed neuropsychological tests evaluating several cognitive domains. The CR was assessed via a cognitive reserve index (CRI) using educational levels and North American Adult Reading Test scores. Change in cognition was assessed using a reliable change index.

Results

At baseline, people with MS performed worse than controls on visual memory. There were no significant group differences on information processing speed, learning, language, and executive functions. Most cognitive domains showed no change over time, and CRI was not a significant predictor in the regression model.

Conclusions

People with MS performed worse on memory tasks at baseline compared with controls. Cognitive change differed between people with MS and controls in executive functions. Although people with MS and controls improved over time, beyond practice effects, people with MS improved less than controls. Overall, no cognitive deterioration was noted over time, and CR did not predict change in cognition. Sample homogeneity in terms of disease stage and CR may explain these findings.

Older age, higher perceived disability and depressive symptoms predict the amount and severity of work-related difficulties in persons with multiple sclerosis

Purpose: This cross-sectional study aims to identify the predictors of work-related difficulties in a sample of employed persons with multiple sclerosis as addressed with the Multiple Sclerosis Questionnaire for Job Difficulties. Materials and methods: Hierarchical linear regression analysis was conducted to identify predictors of work difficulties: predictors included demographic variables (age, formal education), disease duration and severity, perceived disability and psychological variables (cognitive dysfunction, depression and anxiety). The targets were the questionnaire's overall score and its six subscales. Results: A total of 177 participants (108 females, aged 21-63) were recruited. Age, perceived disability and depression were direct and significant predictors of the questionnaire total score, and the final model explained 43.7% of its variation. The models built on the questionnaire's subscales show that perceived disability and depression were direct and significant predictors of most of its subscales. Conclusions: Our results show that, among patients with multiple sclerosis, those who were older, with higher perceived disability and higher depression symptoms have more and more severe work-related difficulties. The Multiple Sclerosis Questionnaire for Job Difficulties can be fruitfully exploited to plan tailored actions to limit the likelihood of near-future job loss in persons of working age with multiple sclerosis. Implications for rehabilitation Difficulties with work are common among people with multiple sclerosis and are usually addressed in terms of unemployment or job loss. The Multiple Sclerosis Questionnaire for Job Difficulties is a disease-specific questionnaire developed to address the amount and severity of work-related difficulties. We found that work-related difficulties were associated to older age, higher perceived disability and depressive symptoms. Mental health issues and perceived disability should be consistently included in future research targeting work-related difficulties.

Depression in Multiple Sclerosis: Epidemiology, Aetiology, Diagnosis and Treatment

Depressive disorders are common in patients with multiple sclerosis, influencing their quality of life and adherence to treatments, as well as becoming more frequent with the progression of the disease and in the secondary progressive form of multiple sclerosis. Patients with multiple sclerosis often experience a typical cluster of symptoms in association with depression, such as fatigue, pain and cognitive impairment. However, the pathogenesis of multiple sclerosis-related depression remains partially unclear, even though genetic, immune-inflammatory and psychosocial factors might be seen to play a role, in addition to the brain structural alterations documented by magnetic resonance imaging studies. The high incidence and burden of depression in people affected with multiple sclerosis are matters of crucial importance. Despite such importance, the efficacy of pharmacologic treatments has been poorly studied and, for the most part, the access to non-pharmacological treatments is partially dependent on the local health system availability. It has been determined that interferon-beta and glatiramer acetate do not cause depressive symptoms; however, no definitive data in this regard are avaible for the newer disease-modifyng medications. In this review, we discuss the diagnosis, prevalence, pathogenesis, clinical aspects, magnetic resonance imaging findings and treatments available in patients experiencing multiple sclerosis-related depression.

Neuropsychiatric syndromes of multiple sclerosis

Neuropsychiatric signs and symptoms occur frequently in individuals with multiple sclerosis (MS), either as the initial presenting complaint prior to a definitive neurological diagnosis or more commonly with disease progression. However, the pathogenesis of these comorbid conditions remains unclear and it remains difficult to accurately elucidate if neuropsychiatric symptoms or conditions are indicators of MS illness severity. Furthermore, both the disease process and the treatments of MS can adversely impact an individual's mental health. In this review, we discuss the common neuropsychiatric syndromes that occur in MS and describe the clinical symptoms, aetiology, neuroimaging findings and management strategies for these conditions.

Cognitive Impairment in Multiple Sclerosis: A Review of Neuropsychological Assessments

Of the more than two million people worldwide with multiple sclerosis, 40% to 65% experience cognitive impairment, many of them early in the course of the disease. Cognitive impairment has been found in patients with all subtypes of multiple sclerosis. Because both pharmacologic and nonpharmacologic interventions may improve patients' brain function, cognitive assessment should be a routine part of the clinical evaluation. Traditional paper-and-pencil neuropsychological tests and batteries can help detect and monitor patients' cognitive problems. Computerized cognitive batteries also show promise. Controversy continues over which test is most reliable at assessing cognitive impairment in both everyday clinical practice and research. Each battery has possible disadvantages, such as practice effects, poor sensitivity and specificity, and questionable applicability to multiple sclerosis. Based on our review of the literature, we describe the tests that are currently being used or that might be used in assessing cognitive deficits in patients with multiple sclerosis, and we summarize the strengths and limitations of each.

The impact of subjective cognitive fatigue and depression on cognitive function in patients with multiple sclerosis

BACKGROUND

The association between subjective cognitive fatigue and objective cognitive dysfunction in patients with multiple sclerosis (PwMS) has been studied, with conflicting results.

OBJECTIVE

To explore the impact of fatigue on cognitive function, while controlling for the influence of depression, disability, comorbidities, and psychotropic medications.

METHODS

PwMS completed a computerized cognitive testing battery with age- and education-adjusted cognitive domain scores. Disability (Expanded Disability Status Scale (EDSS)), cognitive fatigue, and depression were concurrently evaluated.

RESULTS

In all, 699 PwMS were included. Both cognitive fatigue and depression were significantly and negatively correlated with the same cognitive domains: information processing speed, executive function, attention, motor function, and memory (-0.15 ⩽ r ⩽ -0.14 for cognitive fatigue; -0.24 ⩽ r ⩽ -0.19 for depression). Multivariate analysis revealed significant but small independent correlations only between depression and neuropsychological test results, while cognitive fatigue had no independent correlation with objective cognitive function except for a trend toward impaired motor function in highly fatigued PwMS. Depression and cognitive fatigue accounted for no more than 6% of the variance in objective cognitive domain scores.

CONCLUSION

Cognitive fatigue is not independently related to objective cognitive impairment. Depression may influence cognitive function of PwMS primarily when it is severe. Cognitive impairment in PwMS should not be ascribed to fatigue or mild depression.

Fatigue and depression in multiple sclerosis: pharmacological and non-pharmacological interventions

Multiple sclerosis (MS) is a neuroinflammatory condition with a prominent progressive neurodegenerative facet that typically affects young- or middle-aged adults. Although physical disabilities have been in the foreground by being easier to assess, there is an increasing interest in mental disabilities and psychiatric co-morbidities, which have a disproportionally high impact on important outcome measures such as quality of life and occupational disability. In particular, cognitive impairment, depression and mental fatigue, which mutually interact with each other, seem to be of importance in this context. In recent decades, major efforts have been invested in developing more effective disease modulatory treatments. This has resulted in novel therapeutic options and awareness of the importance of early intervention. In comparison, good quality and adequately powered studies on symptomatic treatments of fatigue and psychiatric co-morbidities in MS are rare, and awareness of treatment options is much lower. We here review the existing evidence base for symptomatic treatment of fatigue and depression in MS patients. With regard to fatigue, off-label prescription of alertness improving drugs is common, in spite of all but absent evidence of efficacy. In contrast, a number of smaller studies suggest that physical exercise and fatigue management courses may have some clinical benefit. Very few studies have addressed the efficacy of antidepressants and non-pharmaceutical interventions specifically in MS patients. Therefore, treatment guidelines largely rely on data from non-MS populations. In the future, there is a strong motive to direct additional resources to the study of these important aspects of MS.

Prescribed psychiatric medication among multiple sclerosis patients before and after disability pension: a register study with matched controls

BACKGROUND

Many multiple sclerosis (MS) patients of working ages have psychiatric comorbidity, and 60 % are on disability pension (DP). It is unknown how DP is associated with MS patients' mental health. The objective of this study was to investigate the association between prescriptions of psychiatric medication and time before and after receiving full-time DP in MS patients compared with matched controls.

METHODS

Nationwide Swedish registers were used to identify 3836 MS patients who were granted DP in 2000-2012 and 19,180 DP controls matched on socio-demographic variables by propensity scores. Patients and controls were organized in groups by year granted DP. Adjusted odds ratios (ORs) with 95 % confidence intervals (CIs) were calculated for being prescribed selective serotonin reuptake inhibitors (SSRIs), benzodiazepines, or sleeping agents in 2006.

RESULTS

Both patients and controls, who were not yet on DP in the study year of 2006, had lower OR compared with those who were granted DP in the same year. The OR increased when being closer to DP. MS patients, who had been granted DP 5-6 years earlier, had a higher risk for prescription of benzodiazepines (OR 1.72; 95 % CI 1.16-2.57) than controls (OR 1.14; 95 % CI 1.14-1.18). These patients also had a higher risk for SSRI prescription when compared directly with controls (OR 1.76; 95 % CI 1.44-2.15).

CONCLUSIONS

MS patients have substantially higher odds ratios for being prescribed psychiatric drugs after DP than other disability pensioners. Further research on the association of DP with the mental health of MS patients is warranted.

The Rao's Brief Repeatable Battery in the study of cognition in different multiple sclerosis phenotypes: application of normative data in a Serbian population

Cognitive impairment is prevalent in multiple sclerosis (MS) occurring in 43-72 % of patients with all MS phenotypes. The aim of our study was to assess cognitive performance in different MS subtypes in Serbian population. Rao's Brief Repeatable Battery of neuropsychological tests (BRB-N) was administered to 168 MS patients [37 patients with clinically isolated syndrome (CIS) suggestive of MS, 65 with relapsing-remitting MS (RRMS), 31 with secondary progressive MS (SPMS) and 35 patients with primary progressive MS (PPMS)]. The percentage of cognitively impaired patients in our total MS cohort was 58.9 %. Prevalence of cognitive dysfunction was 40.5 % in CIS group, 36.9 % in RRMS, 96.8 % in SPMS, and 85.7 % in PPMS group. Patients in CIS and RRMS groups performed consistently better all tests of the Rao's battery than patients in SPMS and PPMS cohort. CIS and RRMS groups performed consistently better in all tests of the Rao's battery than SPMS and PPMS cohort. Additionally, difference in the performance of any of the BRB-N tests was not found between CIS and RRMS. However, there was a significant difference between SPMS and PPMS patients in the performance on five tests of Rao's battery. Statistical significance (p < 0.05) in favor of PPMS patients was demonstrated for the following tasks: SRT_lts, SRT_cltr, SDMT, SRT_D, SPART_D. Our study demonstrates that cognitive impairment is frequent in all MS phenotypes. Furthermore, we have found that cognitive deficit is most severe and most frequent in SPMS patients, followed by PPMS subjects and then CIS and RRMS patients.

Information processing speed in multiple sclerosis: Past, present, and future

BACKGROUND

Information processing speed (IPS) is a prevalent cognitive impairment in multiple sclerosis (MS).

OBJECTIVES

This review aims to summarize the methods applied to assess IPS in MS and its theoretical conceptualization. A PubMed search was performed to select articles published between 1 January 2004 and 31 December 2013, resulting in 157 articles included.

RESULTS

The majority (54%) of studies assessed IPS with heterogeneous samples (several disease courses). Studies often report controlling for presence of other neurological disorders (60.5%), age (58.6%), education (51.6%), alcohol history (47.8%), or use of steroids (39.5%). Potential confounding variables, such as recent relapses (50.3%), history of developmental disorders (19.1%), and visual problems (29.9%), were often neglected. Assessments used to study IPS were heterogeneous (ranging from simple to complex tasks) among the studies under review, with 62 different tasks used. Only 9.6% of articles defined the construct of IPS and 22.3% discussed IPS in relation to a theoretical model.

FUTURE DIRECTIONS

The challenges for the upcoming decade include clarification of the definition of IPS as well as its theoretical conceptualization and a consensus on assessment. Based on the results obtained, we propose a new theoretical model, the tri-factor model of IPS.

Variations in and predictors of the occurrence of depressive symptoms and mood symptoms in multiple sclerosis: a longitudinal two-year study

Background

There is limited knowledge regarding how depressive symptoms and a cluster of specific mood symptoms in people with multiple sclerosis (MS) vary over time and how they are influenced by contributing factors. Therefore, the aims of this study were a) to describe variations over 2 years in the occurrence of depressive symptoms and mood symptoms in a sample of people with MS, and b) to investigate the predictive value of sex, age, coping capacity, work status, disease severity, disease course, fatigue, cognition, frequency of social/lifestyle activities, and perceived impact of MS on health, on the occurrence of depressive symptoms and mood symptoms.

Methods

Through using a protocol of measures of functioning and perceived impact of MS on health, comprising of the Beck Depression Inventory, 219 people with MS were assessed at 0, 12 and 24 months. Predictive values were explored with Generalised Estimating Equations.

Results

Proportions with depressive symptoms varied significantly (p < 0.001) from 21 to 30 % between the three time points. Proportions with mood symptoms varied significantly (p < 0.001) from 14 to 17 % between the three time points. Weak coping capacity and reduced frequency of social/lifestyle activities predicted the occurrence of depressive symptoms and mood symptoms, as did the psychological impact of MS on health in interaction with time. For people with MS of working age, not working predicted the occurrence of depressive symptoms and mood symptoms, as did the physical impact of MS on health on the occurrence of mood symptoms.

Conclusions

The occurrence of depressive symptoms and mood symptoms in people with MS vary over a 2-year time period; almost half have depressive symptoms at least once. Health care services should develop strategies aimed at identifying people with MS who are depressed or who develop depressive symptoms. Interventions for alleviating depressive symptoms should consider the individual’s coping capacity and perceived impact of MS on health, and facilitate their ability to maintain participation in valued everyday activities.

Cognitive status in patients with multiple sclerosis in Lanzarote

OBJECTIVES

Cognitive impairment is a common feature in multiple sclerosis affecting ~43%-72% of patients, which involves cognitive functions such as memory, processing speed, attention, and executive function. The aim of this study was to describe the extent and pattern of the involvement of cognitive impairment and psychological status in all patients with multiple sclerosis on a small Spanish island.

PATIENTS AND METHODS

In all, 70 patients and 56 healthy controls were included in the study between February 2013 and May 2013. All participants were assessed using the Brief Repeatable Battery of Neuropsychological Test. The patients also completed instruments to evaluate the presence of fatigue, perceived cognitive dysfunction, and symptoms of anxiety and depression. All procedures were performed in a single session.

RESULTS

Cognitive impairment, defined as a score <1.5 standard deviation on two subtests of the battery, was present in 35% of the participants. The most frequently affected domain was working memory, followed by verbal memory and processing speed. Disease duration showed a moderate correlation with visuospatial memory and processing speed. The Expanded Disability Status Scale score correlated with verbal and processing speed. Verbal memory was correlated with depression symptoms and fatigue.

CONCLUSION

Cognitive impairment was present in 35% of the study population. The most affected domains were working memory and verbal memory. Working memory and verbal fluency deficit are independent factors of disease evolution. Cognitive decline is related to clinical variables and psychological measures such as fatigue or depression but not to anxiety.

A Fresh Look at the Potential Mechanisms of Progressive Muscle Relaxation Therapy on Depression in Female Patients With Multiple Sclerosis

Background:

According to the World Health Organization (WHO) report released in 2000, about 121 million people worldwide suffer from depression. The major depressive disorder (MDD) among multiple sclerosis (MS) patients is one of the most common mood disorders experienced during life. MS patients who simultaneously suffer from depression have reported more severe symptoms of disease and slower adaptation to new conditions, which ultimately increase the cost of treatment.

Objectives:

The aim of this study was to assess the effectiveness of progressive muscle relaxation therapy (PMRT) as an adjunctive therapy for reducing level of depression for MS patients.

Materials and Methods:

This research had the randomized controlled trial design with pre and posttest. Thirty female patients based on criteria of MS and MDD disease, were selected from the MS Society of Shiraz, Iran. Beck Depression Inventory (BDI-II) was administered at pre and posttest. The participants were randomly allocated to two groups (experimental and control). Twelve sessions of PMRT using Bernstein and Borkovec’s method were held for the experimental group. Levin’s test, covariance and ANOVA with repeated measures were used for data analysis.

Results:

Experimental and control groups were compared before and after treatment. Analysis of covariance showed that seven levels of depression decreased in the experimental group and analysis of repeated measure showed that 49% of the changes were related to PMRT.

Conclusion:

According to the results, PMRT is effective in reducing depression. This therapy enables patients to reach relaxation quickly, and thus can cope with depression reactions effectively.

Impact of depression, fatigue, and global measure of cortical volume on cognitive impairment in multiple sclerosis

Objective. To investigate the influence of demographic and clinical variables, such as depression, fatigue, and quantitative MRI marker on cognitive performances in a sample of patients affected by multiple sclerosis (MS). Methods. 60 MS patients (52 relapsing remitting and 8 primary progressive) underwent neuropsychological assessments using Rao's Brief Repeatable Battery of Neuropsychological Tests (BRB-N), the Beck Depression Inventory-second edition (BDI-II), and the Fatigue Severity Scale (FSS). We performed magnetic resonance imaging to all subjects using a 3 T scanner and obtained tissue-specific volumes (normalized brain volume and cortical brain volume). We used Student's t-test to compare depressed and nondepressed MS patients. Finally, we performed a multivariate regression analysis in order to assess possible predictors of patients' cognitive outcome among demographic and clinical variables. Results. 27.12% of the sample (16/59) was cognitively impaired, especially in tasks requiring attention and information processing speed. From between group comparison, we find that depressed patients had worse performances on BRB-N score, greater disability and disease duration, and brain volume decrease. According to multiple regression analysis, the BDI-II score was a significant predictor for most of the neuropsychological tests. Conclusions. Our findings suggest that the presence of depressive symptoms is an important determinant of cognitive performance in MS patients.

Perceived cognitive difficulties and cognitive test performance as predictors of employment outcomes in people with multiple sclerosis

Perceived cognitive difficulties and cognitive impairment are important determinants of employment in people with multiple sclerosis (pwMS). However, it is not clear how they are related to adverse work outcomes and whether the relationship is influenced by depressive symptoms. Thus, this study examined perceived and actual general cognitive and prospective memory function, and cognitive appraisal accuracy, in relation to adverse work outcomes. The possible mediating and/or moderating role of depression was also examined. A cross-sectional community-based sample of 111 participants (33 males, 78 females) completed the Multiple Sclerosis Work Difficulties Questionnaire (MSWDQ), Beck Depression Inventory - Fast Screen (BDI-FS), and questions related to their current or past employment. They then underwent cognitive testing using the Screening Examination for Cognitive Impairment, Auditory Consonant Trigrams test, Zoo Map Test, and Cambridge Prospective Memory Test. Perceived general cognitive and prospective memory difficulties in the workplace and performance on the respective cognitive tests were found to predict unemployment and reduced work hours since MS diagnosis due to MS. Depression was also related to reduced work hours, but it did not explain the relationship between perceived cognitive difficulties and the work outcomes. Nor was it related to cognitive test performance. The results highlight a need to address the perceptions of cognitive difficulties together with cognitive impairment and levels of depression in vocational rehabilitation programs in pwMS.

A systematic review of the incidence and prevalence of comorbidity in multiple sclerosis: overview

Background:

Comorbidity is an area of increasing interest in multiple sclerosis (MS).

Objective:

The objective of this review is to estimate the incidence and prevalence of comorbidity in people with MS and assess the quality of included studies.

Methods:

We searched the PubMed, SCOPUS, EMBASE and Web of Knowledge databases, conference proceedings, and reference lists of retrieved articles. Two reviewers independently screened abstracts. One reviewer abstracted data using a standardized form and the abstraction was verified by a second reviewer. We assessed study quality using a standardized approach. We quantitatively assessed population-based studies using the I² statistic, and conducted random-effects meta-analyses.

Results:

We included 249 articles. Study designs were variable with respect to source populations, case definitions, methods of ascertainment and approaches to reporting findings. Prevalence was reported more frequently than incidence; estimates for prevalence and incidence varied substantially for all conditions. Heterogeneity was high.

Conclusion:

This review highlights substantial gaps in the epidemiological knowledge of comorbidity in MS worldwide. Little is known about comorbidity in Central or South America, Asia or Africa. Findings in North America and Europe are inconsistent. Future studies should report age-, sex- and ethnicity-specific estimates of incidence and prevalence, and standardize findings to a common population.

The incidence and prevalence of psychiatric disorders in multiple sclerosis: a systematic review

BACKGROUND

Psychiatric comorbidity is associated with lower quality of life, more fatigue, and reduced adherence to disease-modifying therapy in multiple sclerosis (MS).

OBJECTIVES

The objectives of this review are to estimate the incidence and prevalence of selected comorbid psychiatric disorders in MS and evaluate the quality of included studies.

METHODS

We searched the PubMed, PsychInfo, SCOPUS, and Web of Knowledge databases and reference lists of retrieved articles. Abstracts were screened for relevance by two independent reviewers, followed by full-text review. Data were abstracted by one reviewer, and verified by a second reviewer. Study quality was evaluated using a standardized tool. For population-based studies we assessed heterogeneity quantitatively using the I² statistic, and conducted meta-analyses.

RESULTS

We included 118 studies in this review. Among population-based studies, the prevalence of anxiety was 21.9% (95% CI: 8.76%-35.0%), while it was 14.8% for alcohol abuse, 5.83% for bipolar disorder, 23.7% (95% CI: 17.4%-30.0%) for depression, 2.5% for substance abuse, and 4.3% (95% CI: 0%-10.3%) for psychosis.

CONCLUSION

This review confirms that psychiatric comorbidity, particularly depression and anxiety, is common in MS. However, the incidence of psychiatric comorbidity remains understudied. Future comparisons across studies would be enhanced by developing a consistent approach to measuring psychiatric comorbidity, and reporting of age-, sex-, and ethnicity-specific estimates.

The evidence for a beneficial role of vitamin A in multiple sclerosis

Vitamin A is an essential nutrient with important roles in immunological responses and in brain development. Its main metabolite is retinoic acid (RA), which is responsible for the neuroimmunological functions related to vitamin A. In the brain, RA is known to have interactions with other nuclear receptor-mediated signalling pathways. RA is involved in plasticity, regeneration, cognition and behaviour. In the peripheral blood, RA plays a major role both in increasing tolerance and in decreasing inflammation, through balancing T-lymphocyte populations. It is likely that RA synthesis may be manipulated by complex cross-talk among cells during infection and inflammation. The role of vitamin A in multiple sclerosis (MS) could be dual: at the same time as it decreases inflammation and increases tolerance of autoimmunity, it may also help in brain protection. The present review discusses the beneficial effects that vitamin A might have for controlling MS, although it must be clearly stated that, at the present time, there is no clear indication for using vitamin A as a treatment for MS. However, the results from the present review should encourage clinical trials with vitamin supplementation as a potential treatment or as an add-on option. Vitamin A acts in synergy with vitamin D, and the immunological homeostasis ensured by these vitamins should not be unbalanced in favour of only one of them.

Predictors of executive complaints and executive deficits in multiple sclerosis

OBJECTIVES

To investigate executive complaints and objective executive deficits and their relations to both depression and neurological function in multiple sclerosis (MS).

MATERIALS AND METHODS

One hundred and twenty MS patients participating in multidisciplinary rehabilitation underwent assessment with the Expanded Disability Status Scale (EDSS), neuropsychological tests of executive function, self-report measures of executive function (BRIEF-A), and depression (BDI-II).

RESULTS

Multivariate regression analysis showed that moderate depression and above (BDI-II > 20) significantly predicted a high degree of subjective executive complaints. Multivariate regression analysis showed that EDSS scores above 4.3 significantly predicted executive cognitive deficit, measured by neuropsychological tests.

CONCLUSION

Among the study variables, depression was the strongest predictor of executive complaints. A high degree of neurological disability was the strongest predictor for executive deficit, measured by neuropsychological tests.